Apparatus for drilling wells



Aug. 29, 1950 H. A. TAYLOR 2,520,517

' APPARATUS FOR DRILLING WELLS Filed oet. 25, 194e sgsneets-sheet 1 Z'NVENTo/e.-

HAR/ans, MECH, FOSTER? HAR/215 ug., 1950 H. A. TAYLOR 3,520,517

APPARATUS FOR DRILLNG WELLS Filed Oct. 25, 1946 3. Sheets-Sheet 2 wm@ g 33 7/ 67 ,aa i ,69 l

#4me/5, MECH, BsTER n? HAR/2.15

Aug 29 l95U H. A. TAYLOR 2,520,517

APPARATUS FOR DRILLING WELLS Filed Oct. 25, 1946 SSheets-Sheet 3 HAqQ/s, MECH, Fos TER H4/ems Patented ug. 29, 1950 UNITED S TATfES PATE NT GFF ICE APPARATUSMFQR DRILLING `WELLS Howard A. Taylor', Long Beach, Califi, assigner ojl' one-half to Manley L. Natland, `Long Beach, 4Calif., and one-half to Lester Callahan hApplication QQherMZE, 1946, Serial NoN/105,691

lMy invention `relates to well drillingand, more particularly, to a noveldrilling apparatus suited to obtain core Sections during continued .drilling and/or a `residual or filamentary core upon Withdrawal ofthe drilling `loit for inspection, repair, or replacement.

The present .invention `contemplates cutting intothe` earth in an annular zoneto leaveacentrai core portion Whichis maximized inlength by being `progressively disintegrated `into core particles, and it is an object of the invention `to provide an improved drilling structure for accomplishingthis.

Bytheterm disintegrating, I have reference to a subdivision ofthe central core portion into cere particles, irrespective `of the size thereof. Such core particles may be relatively small sandlike or `cutting-likeparticles, as when thecore portion is substantially completely disintegrated, or they. may be in the form of larger masses, hereina ter'termed core sections, which are severed, broken, or otherwise removed from thecentrai core portion,'being of substantial size'but representing more than a mere temporarily compacted mass of cuttings from a bit. Such core specimens give `particularly valuable data concerning subterranean strata including geological age, slope and character of subterranean strata, etc.

rEhe present invention contemplates that the core particles, resulting from the progressive disintegration of the -centralicore portion during continueddrilling, shall be discharged to the exterior ci the drilling structure and preferably into a column oi fluid moving upward in the well. For example-it is -commonpractice to drill wells by use `of a `rotary bit `during the time `that a high-density drilling xnudis forced into the zone ci the cutters to-earry upward in the well the cuttings. In the preferred practice of the `present invention, the `core particles are discharged intothe rising drilling `mudand, `if `of `substantial size, can beseparated therefrom at the top or the well to provide aicontinuous curing method giving valuable information as to subterranean strataduring continued drilling. It is an. object of `the present inventionto `provide an improved drilling system ioraccomplishing this.

"The invention also contemplates a `drilling structure having a central passage to receive `the centralicore portion. Disintegration of this core portionfpreierably takes place a substantial but constantdistanee `alcove thecutting felements, whereby `the lowerendof such a` central passage contains a iilamentary core. By use ofi the. pres- 1'7 Claims. (Cl. 'Z55-472) ent invention, this core can be severed or detached from the earths `strata preparatory to liiting the drilling structure, `and can be carried upward With thedrilling structure `when withdrawn for inspection, repair, or replacement. It is` an `object of the 1 present ,p invention to providean improvedapparatus for obtaining Varesidual lanientary. corefrorn a` heavy duty drilling structure when withdrawn from ,the well.

Another object is `toprovide a novel telescoping interconnection between a bit Aand a drive unit; also, ,to `provide a drive u nit `in which a tubular member is disposed to receive the core portion as drilling progresses.

If the disintegration of the icentral core portion breaks core sectionstherefrom, itis desirable that these fbe discharged into the rising fluid in such manner as tominimize abrasion `thereof bytheiluid. 'Ii suoli core sections are discharged from arapidly rotating drilling structure into a body of `fluid whi-ch `isnot rotating or rotating at lower velocity than the `drilling structure, the fluid may unduly `erode a core section extending intoithe-fluid body. fItis `an object or" the `present invention to avoid undue abrasion `at this point, asby deflectifng the fiuidirorn the immediete vicinity roftthe core passage `from which `the cere sections issue.

Further objects offtheinvention lie in the provision oi anov-el rotary `bit for Acutting in an annular zone -toleave `a `central core portion; also,` toprovidea structure in which iluid can be delivered `to fthe `cutters `in van advantageous manner.

Furtherobjects fr and advantages of `the invention Will/be evident fromlthe following des-cription. of exemplary embodiments.

1-llteierring 4to the drawings:

Fig. 1l is autility View, showing diagrammatically` welll` drilling equipment employing `one for-rn of the invention;

Fig. 2 is .a `vertical cross-sectional `viewl ofthe drillingstructure of Fig. l;

Fig. `3 Lis latside View of the upperend of the drilling structure of Fig. 2taken as indicated by Fig. 8 is a side view, partially in section, of a further alternative embodiment;

Figs, 9 and 10 are sectional views of an alternative embodiment, Fig. 10 being taken along the line Iii-lil of Fig. 9;

Fig. 11 is a vertical sectional view of another embodiment; and

Fig. l2 is a vertical sectional view and Fig. 13 is a bottom view of a further alternative embodiment.

Referring particularly to Fig. l, the invention is shown as being used to drill a well or bore I0 in the earth to penetrate strata suggested at I I, a portion of the well being shown cased by a casing l2. Derrick floor I3 carries the usual rotary drilling table I4 turned by a suitable power source, not shown, to rotate a drill column I6 formed of sections of drill pipe I1 coupled by joints i8. At the upper end of the drill column le is the usual swivel 20, the lowering of the drill column being controlled by the position of a travelling block 2i connected to the swivel through a bail 22. The upper end of the drill column is supplied with a fluid, such as a high-density drilling mud, to move downward therethrough and carry the cuttings upward in the well. This fluid may be supplied at high pressure and very considerable volume through hose 23 and pipe 24 by a circulating pump 25.

The drilling structure 3U of the invention is secured to the lower end of the drill column I6, as by a collar 3|. Essentially, the drilling structure includes a bit 32 and a drive unit 33, here shown as a drill collar or sub 34 detachably connected to the collar 3|.

The bit 32 is shown as including a body 35 having a depending head 36 having a central opening 31. The body has two diametrically opposite arms 33 and two additional diametrically opposite arms 33. In the space between each of the arms 33 and the depending head 36 is a peripherally-toothed frusto-conical gage cutter 40 rotating on a suitable pin, not shown, extending between the arms and the head. Similarly, between each arm 39 and the depending head 36 is a peripherally-toothed frusto-conical mill cutter 4 I, similarly journalled on a pin, not shown. The innermost portions of the two mill cutters 4I are preferably spaced a distance substantially corresponding to the diameter of the central opening 31, as best shown in Fig. 5. As the bit 32 turns, the cutters 43, 4I rotate on their respective pins and revolve relative to the central axis A-A of the bit, which axis coincides with the axis of the central opening 31. During rotation of the bit 32, the cutters 4I) and 4I cut into the earth in an outer annular zone, the gage cutters 4U deepening the bore in the outer portion of such Zone and determining the well diameter, while the mill cutters 4I cut into the earth in the inner portion of such outer annular zone and, in the absence of other cutting elements, would leave a core portion of a diameter substantially equal to that of the central opening 31.

In this embodiment of the invention, additional core-cutting means is provided, comprising a core-cutting element detachably extending into the central opening 31. The lower end of this core-cutting element provides teeth 46 which terminate opposite or somewhat above or below the lower portions of the cutters 40, 4I. These teeth are disposed around a central passage 41 of the core-cutting element 45 and cut into the earth in an inner annular zone within 4 the previously mentioned outer annular Zone to leave a central core portion 50 which extends upward in the central passage 41.

The core-cutting element 45 is detachably connected to the body 35 in any suitable manner. As shown, the lower end of the depending head 36 provides diametrically opposite cavities 5|, and the core-cutting element 45 carries arms 52 extending snugly therein and retained by" pins 53.

. The upper end of the core-cutting element 45 comprises a neck 54 extending into the central opening 31, the neck forming essentially a part of the bit body when the core-cutting element 45 is secured in place.

The inner surface of this opening 31 preferably cooperates with the outer surface of the neck 54 to provide a downwardly-directed passage means for jetting drilling mud or other fluid at high velocity toward the bottom of the well, preferably near the junction of the inner and outer annular zones, respectively penetrated by the teeth 46 and by the cutters 46, 4I. In the preferred construction, the inner wall of the central opening 31 is cylindrical and engages snugly the outer wall of the neck 54. However, this outer wall provides longitudinal grooves around its periphery, these grooves facing the wall of the central opening 31 and cooperating therewith in dening a plurality of passages 55, best shown in Fig. 5. The upper ends of these passages communicate with a chamber 56 of the bit so that the drilling mud or other uid in this chamber under high pressure will be jetted downward through the passages 55 to impinge on the floor of the well and aid the drilling operation, either by a hydraulic cutting, Similar to that eiected in hydraulic mining, or by directing the cutting lluid in the immediate vicinity of the teeth 33 to facilitate the cutting action and remove cuttings. Similiary, high-pressure drilling mud or other luid may flow from the chamber 56 through four small passages 51, respectively directed toward the upper portions of the cutters 46 and 4I to wash the cuttings therefrom and facilitate the cutting action thereof. As in the usual practice, such drilling mud or other fluid rises in the well II) around the drilling structure 30, as indicated by arrows 58, carrying the cuttings to the surface of the ground where the fluid and its associated cuttings discharge through a pipe 59 into a sump 60.

The sub 34, forming the drive unit of this embodiment of the invention, provides an externallythreaded neck 6I threaded into a cavity 62 of the bit. The uppermost end of the sub 34 is suitably connected to the collar 3l or to some other element of the drill column I6. As shown, the upper end of the sub includes a threaded neck 63 threadedly received by the collar 3I. In the present invention, the sub 34 is preferably formed as a massive tubular member relatively easy to fabricate and providing a longitudinal passage 64 through which mud or other uid may flow to the chamber 56 under high pressure.

The invention provides a means for progressively disintegrating the central core portion 50 at a position within the drilling structure 30, and preferably within the drive unit 33. While various disintegrating means can be employed, the preferred embodiment of the present invention contemplates the use of a structure for subjecting the central core portion 5!) to bending stresses, e. g., by providing an axially curved core passage means along which the central core portion 50 is moved to break core sections from the cenasesinar tralooreportion: Anexemplary structuretir-"tins` type-is-best s-li'oW-ninFlgs 2. v

Referring particularly to*` Fig. 2,- theV centrallpassage- 411' is counterbored to= receive the lower" end of a tubular member 65 traversing thecharnber- 55 andi of4k an internal-sizeslightly larger than the central core portionl). In this respect;l the central passage 41` may besteppe'dinksize atanq intermediateposition, as suggestedinfFig; 2 andi may bek off slightly smaller diameter thanu the' interior'4 of the tubularmem'ber 652 Telescoping with an upwardly-extending tubular portion off the` tubular member' Sil and coaXial-Withitlie'iax-is A--a is a lower tubular portion 6G-of a tubularf member^61; these-two tubular portions' cooperating informing a core-receiving passage 6'8'2 If desired, the lower end offthe'tubular rnen'lbery B1? maybe slightlyenlargedto'receive the `upwardlyextending tubular portion of thetubular 'member' 65"n or such enlargement can bel eliminated; inI which eventthat portion of the core-receiving passage tilS providedby the lowertubularportion 66 can be of slightly larger diameter thanthe interior of theV tubular memberY 65l In either event@ it is desirable that the' lower tubular por-- tionf 66' telescope withthe upwardlyeextending tubular portion of thel tubular member 65` when the bit 32is connectedto the' drive unit 33'. The junction is' preferably relatively snug to prevent any of" theA drilling mud or` other fluid moving; from' the chamber 56 betweenthe telescopin'gportions and` into the core-receiving` passage B8.. Such drilling mud or` other. fluid: reaches the chamber 56'by :dow through aliiuid-cond'ucting space 69. within the longitudinal passage 6.4 outside the tubular member 61'.' Ih this embodiment of i the invention, no centering, support required. between the lower tubular. portion 66. and. the. sub 3'4lasthe tubular member 65` of the bit may serve in this. capacity.

The tubular member 61 provides an` upper tu.- bular` portion 16. havingan axis angling 4from `the axis,A.--A. For example, the tubular member 6,1. mayb be bent. intermediate its endsjbelore'being` mounted in` the sub 3.4,.the-upper tubular portion `forming a continuation .of the .core-receiving passage 68.. In the embodiment shown in lig.,2,` the sub 3IivprovidesanV opening 1-I-ang1ing` upwardlyfandxedlyf receiving the-upperA end of the tubular member 6:1. The upper endof the tubular member- 61 thus provides an orifice 12 open`l ingf: on the exterior of the, drive unite. g., the.-` subf34, for expulsion of disintegratedmaterial.

As drilling progresses, the central` coreportion will rise intdthe bent portiorrofftlfie` tubular, mem.- ber E1. If still aiiixed totheearth, such central"` core portionA will be. stationaryv relative. to the.: now-oscillating upper tubular portion 1l); This isthefusual mode-of operation; However; if. the central` core portion has for some reason: been.. severed from the earthitwills rotatewith the'i bit 324. and drive unit 33.4 In eitheievent; forcing oftsuch a central coreportionrintoithef bentporf tion. ofithertubularz member 61'wi1l cause disinFU teg-rationfdue, for example, totheapplication of bending forces as thetcentralcore portion is guidif edby. the inner walls of the tubular member E1 along. thecore-eonducting passage. Thus,- when the` upper,l end= of the central: core portion con-- tacts an arcuate `wall 13 formed by the-upper tu bular-l portion itwillbe forcedsidewardiinto contact?V withi an opposingwall 14` and aV bendingstresswill be establishedin the -core Aportiontendfing todisintegrateit; Dependingpartially-upon? tlie` character ofAg the formation', this disintegrais` tion will be into core particlesA of size varying. from minute subdivisions of the core portion to In drilling through hard vformations, sizable chunks are broken fromthe-` sizable core sections.

centrallcore portion, usually along natural cleavagee planes; such core sections being indicated by the numeral 15; These core seetionswill stackAK upin the upper tubular portion 10 to be progres-Y sively forcedfromlthe or-iiice 12;

Irrthe event that sizable. core sectionsr 15 arci` formedland-progressively pushed from the Vorifice eachvoore section .may be poised in the' orifice 12with'its outer end projecting into the body of uid inthe Well around the'drive unit 33. Such bodyoff fluid will'be flowing upwardly at a rate depending. upon the cross-sectional area availablefor flow and uponthe rate of pumping. Such.

explusion is encountered, a` deilector means' 16- mayf be employed, as suggested in Figs. 2,` 3, and 4.

Such-adenector means may include a1 deflectorA 17"' extending outward from the drive unit, preferably adjacent' the leading side of the oriiice 1'21 Forexample, ifthe drive unit is rotatingini.

the=di1ectionof 'arrow 18 of Fig. 4, the action will be as=if `the body of fluidwere rotating past the orice in avdirection indicated by a-rrow- 19t, andi the leading side of the orifice 12y will be thatside indicated by the numeral 80. The deflector `il'iwill deflect the fluid outwardly from the immediate'vicinity of the orifice 12 andrelieve the poised-for-discharge core section'frozm undue erosive action or duid-induced pressure Which= 'would-otherwise bepresent. Preferably, thedefiector-1Tprovides a lower portion 82 extendingto aposition-below the orice 12. This portion 82 may serve further to protect the poised core section against undue erosion because or upward velocitlypftlie body of fluid; No corresponding portion is-usually needed at the upper end of tlie=orice where, in fact, the upper end of the` untili it is sufficiently expelled from the passage off the uppertubular portion 10 to enter theA ris'- ingfluid for transportation to the surface of theground' wheresuch core sections can be caughton a screen 83 for inspection.` Iii-desired,

the core sections can be washed preparatory tov such inspection by a Water-spray device 84;

Irrespective of whether or not core sectionsa're collected during continuous drilling, it is oftendesirable to remove with the bit when withdrawnY for inspection, repair, or replacement a fila-v mentaryfcoresection, e. g., at least a part of theA central core portion 59 within the drilling structure 3U? Theinvention contemplates Yany suitable meanslfor severing the central core portion fromthe=earth, preferably at a position adjacent they bottom" of the bore, preparatory to removal of the` bit fromthe well.-

Such severancev can b'ei effected by stopping the circulation of drilling mud while continuing to rotate the bit rapidly often with substantially increased cutting pressure applied to the bit. This burns in the core portion, causing it to wedge tightly in the lower section of the central passage 41 and causing severance from the earths strata. A core-catcher means, such as shown in Fig. l2, can be added to assist in holding the core portion in position. Thereafter, 'the core portion or residual filamentaryicore in the drilling structure can be raised to the surface of the ground, whereupon it can be forced from the confining passage of the drilling structure by any suitable means to represent the strata during the last few feet of drilling. The embodiment of Figs. 6 and 7 differs from that previously described primarily in providing a sectional structure in which a portion of the tubular member t? is removable from the drive unit 33. includes upper and lower sections 85 and 86 threadedly joined at El?. The tubular member Si is made sectional and comprises an upper tubular portion 'l0 extending in the opening 1|, as previously described, but being of somewhat sharper radius of curvature. Corresponding to the lower tubular portion 6B is a removable tubular member 80 providing an upper end telescoping within the upper tubular portion 10 adjacent the junction of the sections 85 and 80, the ends of the telescoping elements being beveled, as indicated, to facilitate the telescoping action when the sections 85 and 80 are joined. The telescoping joint is preferably snug to prevent mud or other fluid entering the upper tubular portion 10 from the fluid-conducting space 69 now formed within the longitudinal passage 54 around the removable tubular member 88. The lower end of the removable tubular member telescopes with the upwardly-extending tubular portion of the tubular member 65 of the bit, as previously described, but one or more arms 209 center the tubular member 65 with respect to the bit body 35 and serve as stops to carry the weight of the removable tubular member 88. Such arms 89 can be eliminated in the event that the removable tubular member 88 provides a lower enlarged or bell-shaped portion similar to that illustrated in Fig. 2 for receiving the upper end of the tubular member 05. To aid in centering the removable tubular member 88 in the longitudinal passage 66, spider-like arms 90 may extend radially therefrom to slidably engage the inner wall of the longitudinal passage.

The'embodiment of Figs. 6 and 7 can be employed with any suitable bit having a central passage through which the core portion rises into the core-receiving passage |53 as drilling progresses. Disintegration of the core portion takes place in the curved upper tubular portion 'l0 and the resulting disintegrated material or core particles, whether large or small, are expelled from the orifice l2, which can open on the exterior fluid or which can be provided with the defiector means 'i6 previously described. However, this embodiment of the invention facilitates removal of any residual or lamentary core raised to the surface of the ground in the core-receiving passage 08 when the drilling structure is lifted from the well. Such residual or iilamentary core can easily be removed by unscrewing the sections 85 and 86 and drawing the removable tubular member S8 from the drive unit 33. A relatively long length of the residual or iilamentary core may be withdrawn with the removable tubular mem- In this embodiment, the drive unit 33 ber or the tubular member may be lifted without detaching the bit 32 to leave a columnar core in thev longitudinal passage S4, the column being broken to remove a desiredv section thereof for inspection.

The embodiment of the drive unit shown in,

Fig. 8 is quite similar to that shown in Fig. 2

except that the sub 34 is made more massive and provides an upper corner 9|. The opening 1| in this embodiment extends to the corner 9| so that the orifice 'I2 faces more nearly upwardly than in the previous embodiments. This gives additional clearance space between the drive unit 33 or the collar 3i and the outer Wall of the well.

Figs. 9 and l0 show an alternative bit construction in which the core cutting element 45 is constructed substantially as previously de in place.

In this embodiment the outer ends of the arms |00 are detachably connected to the sub 34, constructed as previously described. In the preferred construction, the lower end of the sub 31| provides four radial slots ldd receiving the outer ends of the arms |06. These arms may be heldin the slots |04 permanently, as by being welded thereinyor temporarily, as by being held in place by screws |05. The bit body provides a shoulder |06 which engages the lower faces of the arms |00 when the bit 32 is attached to the sub 34. This arrangement supports the core cutting element independent of the cutters d0 and lll. This construction has the additional advantage that the mounting means forv the core cutting element is disposed a substantial distance from the zone of cutting, thus eliminating any possibility of dropping the core cutting element if it should be severely abraded.

As before, the upper end of the tubular member |0I preferably telescopes with the lower portion of the tubular member 6l of the sub. The drilling mud moves between the arms |00 into the chamber 56 and discharges toward the cutters through the passages 51. A small portion of this mud may also be discharged through the peripheral passages 55, as previously described.

Fig. 11 shows a similar structure applied to a pin-type bit having a neck -||0 received by a threaded socket at the bottom of the sub 34. In this embodiment, the outer ends of the arms |00 extend into slots ||3 formed in the neck H0 but otherwise corresponding to the slots |04 of the previously-described embodiment. The sub 34 provides a shoulder I4, corresponding in function to the shoulder |00 previously described.

The embodiment disclosed in Figs. l2 and 13 employs rotary mill cutters |20 as core cutting elements whereby the central core portion 50 is shaped and sized by the lowermost sections of toothed frusto-conical portions |2011 of rollertype cutters which provide main teeth |201) facing and cutting into the earth in an inner annular zone, the teeth |202) being formed on a main frusto-conical portion or face of each cutter. The mill cutters |20 are shown as rotatably mounted on inclined pins |200 extending inwardly from arms |2| at such angle that a line drawn inthe plane of the portion |20a of either cutter from the axis of the lcorresponding pin |200 to the lowermost tip of the cutter will lie substantially parallel to the axis of rotation of` assoit-17 the bit'` body whereby the teeth on the portion l'Z will, shape and size the core portion 50. This embodiment also provides rotary gage cutters` |213; best shown in Fig. 13 which are journalled, on pins |23a extending outward from a depending head |24 of the bit body, these cutters determining the size of the bore. The cutting zones of the cutters |20 and |23 overlap.

In this embodiment, the tubular member is carried` by arms IEi, as described with reference to Fig. 11. However, the lower end of the tubular member ||l| extends through a central opening` |26 of the depending head |24. Preferably, the lowermost end of the tubular member |01 extends downwardly into` the taperedspace between the mill cutters |20, being shown as terminating in a tapered portion, |23 terminating` a short distance above the bottom of the bore. This tubular member provides a central passage |39 which is slightly larger than the central core portion e. Wit-h the construction shown the central passage |39 extends downwardly to a position quite close to the base of the central core portion 5D so as to minimize any unconned section or the central core portion.

With the embodiment of Fig. l2, it is usually unnecessary to provide the peripheral passages 55 although these may be employed if desired. Itis usually preferableto direct the mud through passages |32 of the depending head, these passages being directed respectively toward the four rotary cutters.

It is often desirable to provide a core-catching means in the lower portion of the tubular member IDI, for example, the core catcher |35 of the conventional fingered type shown. Such a corecatcher means aids in severing and lifting the central core portion with the bit when raised.

It will be clear that various types of bits can be used with any of the embodiments of the drive unit 33 herein disclosed; also, that various other changes and modifications may be made without departing from the spirit of the invention as deiined in the. appended claims.

I claim as my invention:

l. Apparatus for drilling into the earth, including: a rotary bit having a central opening and cutter means disposed therearound for cutting into the earth in an outer annular zone; a corecutting means comprising a body positioned in said central opening, said` body providing teeth atl its lower end, said teeth cutting in an inner annular zone within said outerA annular zone to leave a central core portion, said body of said core-cutting means including a central passage for receiving said central core portion as drilling progresses; a first tubular member carried by said body of said core-cutting means and providing an` upwardly-extending tubular portion; a drive unit operatively connected to said bit to rotate same; a second tubular member extending in said drive unit` and providing a lower tubular portion telescoping with said upwardly-extending tubular portion of said' first tubular member; and walls defining 4a passage communicating between .said` second tubular member and the exteriory of said driveunit and having anaXis angling from the axis of said second` tubular member.

2. Apparatus for drilling into-the earth, including.: a` bit body having av chamber; a tubular member carried by said bit body and extending along said chamber, said tubular member providing an upper tubular portion; cutting means carried by said bit-body for cutting into the earth an annular zone to; leave a central core portion, said tubular member being of a size to receive said core portion as drilling progresses; walls dening a passage means communicating between said chamber and said cutting means for conducting a fluid from the former to the latter; a drive unit detachably connected tosaid bit body and providing a `longitudinal passage; and means for, disintegrating said central core portion within said drive unit, said means including a` drive unit tubular member having a lower tubular portion telescoping with said upper tubular portion or said tubular member carried` by said bit body near the zone of detachable connection between said bit: body and said drive unit to receive said core portion, said means including a passage means angling from and across the axis; of `said drive-unittubular member and opening on the exterior ci said drive unit on one side thereof, said drive-unit tubular member extending in and being of smaller size than said longitudinal passage to provide a fluid-conducting space communicating with said chamber of said bit body.

`3; A drive means` for operatively interconnecting a rotary elementand a rotary earth-boring bit providing cutting elements adapted to cut into-the; earth in an annular zone to leave a central core portion. said drive means including: a drive unit including means for connecting same to said bit and said rotary element, said drive unit including a longitudinal passage; a tubular member and means for positioning same in said longitudinal passage, said tubular member providing a lower portion withinsaid longitudinalA passage to define a duid-conducting space for conducting fluid from said rotary element to said bit, said lower` portionproviding a core-receiving passage-of a size to` receive said central core portion, said tubular member providing an upper end in said longitudinal passage; and a coredisinteg-rating means for progressively disintegrating said core portion, said core-disintegrating means including a passage opening on the exterior of said drive unit and including a wall bounding said passage and angling across' the axis` of said upper end of said tubular member to be, contacted by saidy core portion to disintegrate samel intol corel particles, said passage` conducting said core particles to the exterior of said drive unit, saidcore-disintegrating means providing a dependingtubular portion telescping with said upper end of `said tubular member.

4. Apparatus for drilling into the earth, including: a rotary bit providing means for cutting into the earth inl an annular zone-to leave a central core` portion, said bit including an upwardlyextending threaded portion and an upwardlyopening chamber within said threaded portion; a tubular member attached to said bit and extending upwardly in said chamber, said tubular member having an internal diameter sufiicient to receive said core portion; a tubular drive unit having a depending threaded portion detachably connectedr to` said upwardly-extending threaded portionA of saidi bit at a position adjacent the upper end of said tubular member; a drive-unit tubular member Within said tubulal` drive unit and having azl'owerend telescoping with the upper end of said: tubular member attached to said bit when said' bit` and said drive` unit are connected, said tubular members cooperating to denne a core-receiving passage receiving said central core portion andi being separable at their telescoping junction when said bit is detached from said `drive unit; and means near the upper endof said drive-unit tubular Vmember for subjecting said core portion to bending stresses to subdivide same into core particles, said last-named means including means for conducting such core particles to the exterior of said drive unit as drilling progresses.

5.V Apparatus as dened in claim 4, in which said upper end of said tubular member of said bit extends upwardly in said chamber no farther than the upper end of said upwardly-extending threaded portion of said bit, and in which the lower end or said drive-unit tubular member extends downwardly in said tubular drive unit a distance no farther than the lowermost end of said depending threaded portion of said drive unit.

6. An apparatus for drilling wells with the aid of a circulation of iluid moving upwardly in the drilled portion of the well and by use of a bit providing cutting elements disposed around but spaced from the axis of the well to cut into the earth in an annular zone when the bit is rotated, thereby leaving a central core portion extending upwardly into said bit, said apparatus including:

'a tubular drive unit; walls defining a core-passage means in said drive unit to receive said core portion; means for progressively disintegrating an upper section of said core portion in said core-passage means and including an orifice positioned to open on the upwardly-moving fluid in the well to discharge the disintegrated material thereinto; and a deflector means extending outwardly from the periphery of said drive unit adjacent said orice and into the upwardly-moving fluid for deecting said fluid away from said Orifice.

7. App-aratus as defined in claim 6, in which said deilector means includes a deflector element extending outwardly from the periphery of said drive unit adjacent the leading side of said orilce to deflect said fluid from the immediate vicinity of said orifice during turning of said drive unit.

8. Apparatus for drilling into the earth and adapted for use with a tubular drive unit containing a tubular member having a lower end and an upper portion, said drive unit including means for disintegrating a core portion, said apparatus including: a rotary bit comprising a bit body, a pair of depending arms and a head positioned between said arms and spaced therefrom to dei-lne cutter spaces; a pair of rotary cutters; means for journalling said cutters in said cutter spaces, said cutters providing teeth, the innermost portions of said teeth being spaced from the axis of rotation of said bit body to leave an upstanding core portion; and walls dening a core-receiving space of a size to receive said core portion and extending from a lower position below the axes of rotation of said cutters upwardly through said bit body, said walls including a tubular member attached to said bit and bounding at least the upper portion of said corereceiving space, said tubular member extending upward a sufficient distance to telescope with said lower end of said tubular member of said drive unit.

9. Apparatus for drilling into the earth and adapted for use with a tubular drive unit containing a tubular member having a lower tubular portion and an upper portion and containing a core-disintegrating means, said tubular drive unit having a threaded portion adjacent the lower end of said lower tubular portion, said apparatus including: a rotary bit body providing an upwardly-extending threaded portion and an upwardly-opening chamber within such threaded portion, said upwardly-extending threaded portion being adapted to be threadedly connected to said threaded portion of said drive unit; a plurality of cutters carried by said bit body to cut into the earth in an annular zone to leave a central core portion, said bit body having an opening for receiving said core portion; and a tubular member carried by said bit body coaxially with said opening and of a diameter to receive said core portion and to telescope with said lower tubular portion of said tubular member of said drive unit, said tubular member carried by said bit extending upwardly in said chamber and conducting said core portion to said lower tubular por-tion.

10. Apparatus as dened in claim 9, in which said tubular member carried by said bit extends upwardly in said chamber no farther than the upper end of said upwardly-extending threaded portion.

11. Apparatus as dened in claim 9, in which said chamber includes a bottom wall having an opening of a size to receive and retain the lower end of said tubular member carried by said bit, this tubular member providing an upper portion extending along said chamber to telescope with said lower tubular portion and being supported solely by its said lower end being retained in said opening of said bottom wall.

12. Apparatus for drilling into the earth, including: a rotary bit having a central opening and cutter means disposed therearound for cutting into the earth in an outer annular zone; a core-cutting means comprising a, body positioned in said central opening, said body providing teeth at its lower end, said teeth cutting into the earth in an inner annular zone within said outer annular zone to leave a central core portion, said body of said core-cutting means including a central passage for receiving said central core portion as drilling progresses; a drive unit operatively connected to said bit to rotate same, said drive unit providing a longitudinal passage axially aligned with said central passage of said core-cutting means; and a tubular member providing a lower tubular portion having an axis aligned with the axis of said central passage, said lower tubular portion extending downwardly in said longitudinal passage and being of smaller size than said longitudinal passage to provide a fluid-conducting space, said tubular membel1 providing an upper tubular portion in open communication with said lower tubular portion and r with the exterior of said drive unit but having an axis angling from the axis of said lower tubular portion; and passage means disposed adjacent the periphery of said body of said corecutting means for conducting iluid from said fluid-conducting space to said core-cutting means and toward the bottom of the bore at a position adjacent the junction of said zones.

13. Apparatus for drilling into the earth, said apparatus including: a rotary bit having a central opening and cutting elements disposed therearound to cut in an outer annular zone; corecutting means comprising a body extending into said central opening, said body providing teeth cutting in an inner annular zone within said outer annular zone to leave a central core portion, said core-cutting means including a central passage to receive said central core portion as drilling progresses; means for detachably connecting said body of said core-cutting means within said central opening of said bit, said con- 13 necting means including an arm on said corecutting means, walls dening a cavity in said bit to receive said arm, and means for securing said arm in said cavity; and means for disintegrating said central core portion at a position above said teeth of said core-cutting means.

14. Apparatus ior drilling into the earth with the or a cutting iiuid, said apparatus including: a rotary bit providing a body having a central opening providing an internal Wall, said bit including cutting elements carried by said body ior cutting into the earth in an outer annular gone, said body providing a chamber for receiving said cutting fluid; a core-cutting element having a central passage and providing teeth disposed around the lower end thereof; means for mounting said core-cutting element within said central opening, said teeth being adapted to out in an inner annular zone Within said outer annular Zone to leave a central core portion received by said central passage as drilling prograsses; and passage means within the connes or said contrai opening oi said bit body and coininunicating with said chamber for conducting cutting nuid to said teeth, said core-cutting element providing longitudinally-extending peripheral grooves cooperating with said internal wall of said central opening to denne said passage means.

15. Apparatus for drilling into the earth, including: a rotary bit providing means for cutting into the earth in an annular zone to leave a central core portion, said bit including a tubular member having an upwardly-extending tubular portion of an internal diameter to receive said core portion; a tubular drive unit detachably connected to said bit at a position adjacent said tubular member, said drive unit providing a tubular member cooperating with said drive unit in providing an annular mud-conducting space, said tubular member of said drive unit having a lower tubular portion telescoping in substantially fluidtight relationship with said tubular member of said bit when said bit and said drive unit are connected, said substantially duid-tight relationship preventing iow oi mud from said annular mud-conducting space through the telescoping junction of said tubular members, said tubular members cooperating to define a core-receiving passage receiving said central core portion; and means for disintegrating said core portion within said drive unit as drilling progresses and as said core portion rises to a position above the telescoping junction of said tubular members.

16. Apparatus for drilling into the earth, including: a rotary bit providing means for cutting into the earth in an annular zone to leave a central core portion; a tubular member secured to said bit and having an upwardly-extending tubular portion of an internal diameter to receive said core portion; a drive unit providing a tubular member having a depending lower tubular portion telescoping with said upwardly-extending tubular portion of said tubular member of said bit when said bit and said drive unit are connected, said tubular portions cooperating to dene a core-receiving passage receiving said central core portion; means adjacent the telescoping junction of said tubular portions for detachably connecting said bit to said drive unit, said telescoping tubular portions separating upon removal of said bit from said drive unit and moving into telescoping relationship when said bit is attached to said drive unit; and means for disintegrating said core portion within said drive unit as drilling progresses and as said core portion rises to a position above the telescoping junction of said tubular members.

17. Apparatus for drilling into the earth, including: a rotary bit providing means for cutting into the earth in an annular zone to leave a central core portion; a tubular member secured to said bit and having an upwardly-extending tubular portion of an internal diameter to receive said core portion; a drive unit detachably connected to said bit at a position adjacent said tubular member; a removable tubular member positioned in said drive unit and having a lower tubular portion telescoping with said upwardlyextending portion of said tubular member of said bit when said bit and said drive unit are connected, said tubular portions cooperating to dene a core-receiving passage receiving said central core portion, said removable tubular member providing an upper end; means for disintegrating said core portion at a position above said upper end of said removable tubular member, said disintegrating means including a wall angling across the axis of said removable tubular` member above said upper end thereof to be contacted by said core portion to subdivide same, said disintegrating means including a passage for conducting the subdivided material to the exterior of said drive unit; and means for removably connecting said disintegrating means and said upper end of said removable tubular member.

HOWARD A. TAYLOR.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,306,674 Esseling June 10,1919 1,596,975 Humason Aug. 24, 1926 1,644,947 Phipps Oct. 11, 1927 1,780,447 Shows et al. Nov. 4, 1930 1,785,405 Candee et al. Dec. 16, 1930 1,867,024 Oliver July 12, 1932 1,895,526 Solum Jan. 31, 1933 1,898,937 Brewster Feb. 21, 1933 10,978,085 Howard et al. Oct. 23, 1934 2,024,450 I-Iunt Dec. 17, 1935 2,071,916 Bozeman Feb. 23,1937 

